Emulating Access Grid features at Web endpoints: a developer's view

This paper presents the development experience and the evaluation of a system to emulate interactive features of Access Grid virtual rooms (venues) at Web endpoints. The system includes a toolset to demultiplex Access Grid sources, transcode them to adequate formats for Internet distribution and store the resulting multimedia streams in repositories in real time. A specialized server asynchronously delivers those streams to standard Web browsers, which synchronize them and emulate typical Access Grid interactive features such as multiple windows or dynamic video selection. Web browsers can compose multiple independent streams. We call the resulting paradigm Presentations on Demand. From the point of view of software practice, the system relies on a combination of SMIL scripts, CSS and Javascript. Copyright © 2008 John Wiley & Sons, Ltd.